Okay - L200 4 Life 2005 pickup - just passed mot - oil change etc - all fine and dandy. Go to shop - running sweet - park up - come back out half an hour later - start the engine and it revved to redline and blew black soot out the exhaust ! near on had heart failure ! - switched engine off no problem - any ideas as to cause as no garage near me will take a look at it (prob due to its age )

To rev up it will only mean one thing excess fuel, I would check the intercooler for oil first as the turbo might be passing... that being clean then you might have an injection pump issue, not really much else you can do to diagnose unfortunately

Thanks Mikeinatruck - great answer. Okay... The intercooler is clear and the turbo's not sucking oil. Also it wont start if the immobiliser is disconnected. No white smoke and the engine turns off okay with the key.

So... It's a runaway fuel supply problem. I disconnected the tps and it made no difference - just reved right up! That suggests Injector pump or ECU. If i replace th injector pump can I get the car running again? or does it require dealership re-mapping?

ecu gets my vote! take it out for inspection! that of a bad earth or earth JC

The diesel pump does have some electrickery to match with the TPS so could be a failure there causing it to show full throttle

Injection pump can just be swapped out ecu requires more work as you'll need immobiliser ecu to match and the keys.. You could disconnect the injection pipes, bag the ends and then do an extended turn over and see what sort of injection quantities you are getting before pulling all the pump off.

Thank you all for your help. Previously I was unable to communicate through the OBD11 and assumed it was my kit - the garage told me they had connected and got a code relating to the injector pump. Not confident that they know what they're doing I thought I'd try one more thing... very obvious. I disconnected the battery to get the ecu to try a 'hard' reset. unbelievably this seems to have sorted the problem! So far the car has been performing perfectly but I'm concerned it may happen again. To me, it suggests an issue with the electronics... ECU?, Sensors? wiring connection? who knows! The fact that it's self 'corrected' on rebooting the ECU suggests some kind of signal anomoly. If it happens again, I'll be back here whinging - in the meantime, if this happens to anyone else, try a simple battery disconnect first!

when it happens again it will maybe not for a while pull the ecu out and i inspect it

You can get a flash code of it easy enough if the eml comes on again